Explanation of this Python language feature? [x for x in x for x in x] (to flatten a nested list)

[Mark H Harris]

On 3/28/14 10:51 PM, Steven D'Aprano wrote:

>> Why must
>> everyone in the world be stuck with a U.S. Royal typewriter keyboard for
>> two or three hundred years?
>
> You are being patronising to the 94% of the world that is not from the
> USA. Do you honestly think that people all over the world have been using
> computers for 30 or 40 years without any way to enter their native
> language?

You think ~sooo three dimensionally.

Picture this  ~a unicode keyboard with morphing keytops (digital ink, 
light emitting); a standard layout of keys that are touch sensitive, are 
meta operative, and are able to input *every* language on earth (as well 
any symbol). The keyboard may emit light, but not necessarily. The keys 
may be raised, but not necessarily; they have a glassy feel, soft, 
sensual, and completely programmable. Code point pages (key top mappings 
literally) are selectable on|off screen. The keyboard is obviously 
wireless, and the entire keytopsection is mouse-able; the whole keyboard 
is a pinting device, with diff sections for scrolling &c.

This keyboard will be standard in about 25 years... none exist today.

One of the things I do is biblical and classical language support and 
translation (Latin, Hebrew, and Greek).  I do translation work as well 
as papers, research, &c; I need four full keyboards.  I'm getting by 
fairly well with the macs key mappings, but what I'm really after is the 
21st century keyboard I'm dreaming about above.

Think, virtual keyboard, on a keytoplayout... but separate from any 
touchable screen. And, think mac keytops (or flatter) not the plastic 
IBM typewriter like keyboards of today. Think beyond.

marcus